The Sun's 10th Planet... Sedna?

dsanfte writes "While NASA remains intentionally vague, promising only a news conference Monday, The Australian has the details. The new planet, dubbed Sedna after the Inuit goddess of the sea, is 3 billion km further from the sun than Pluto, and is slightly smaller at 2000km in diameter. This discovery has apparently reignited the debate as to how big a solar object must be in order to qualify as a 'planet', but it is significant nonetheless."

A lot of astronomers don't want to count Pluto

[Anonymous Coward]

So why should we start counting an even smaller "planet"? Pluto gets grandfathered in, and that's it.

Re:A lot of astronomers don't want to count Pluto

[Concerned Onlooker]

You exclusive club-types are all alike....

Here, a rule that I propose.. planet versus other:

[deathcow]

If it's big enough to assume spherical shape by the action of gravity, it's a planet.

Re:Here, a rule that I propose.. planet versus oth

[daeley]

By that logic, Anna Nicole Smith qualifies. ;)

Re:A lot of astronomers don't want to count Pluto

[WorkEmail]

I say we put up a huge sign next to the Sun that says "You must be at least this big (insert huge red line) to ride this ride."

Re:A lot of astronomers don't want to count Pluto

[c1ay]

So where's the line between asteroid [wikipedia.org] and planet [wikipedia.org]? IMO, Pluto [wikipedia.org] should be labeled an asteroid since it's smaller than even our own moon [wikipedia.org]. Of course, there are also asteroids with moons but yet, they are considered asteroids, not planets. And what makes a comet [wikipedia.org] a comet and not an asteroid, it's orbit? It would certailny seem that agencies like NASA that are so concerned with being precise in other areas could could come up with a more precise classification system.

Re:A lot of astronomers don't want to count Pluto

[Rick the Red]

Comets are snowballs; asteroids are rocks. Oversimplification, but you get the idea.

Re:A lot of astronomers don't want to count Pluto

[Guppy06]

"asteroids are rocks"

We should use this for the demarkation between "asteroid" and "planet." An asteroid is one big chunk of rock. A planet is a bunch of little rocks held together by their own gravity.

If Pluto primarily orbits the sun and it's dense enough to hold on to an atmosphere from time to time, why shouldn't it be considered a planet?

Re:A lot of astronomers don't want to count Pluto

[Martin Blank]

A large number of known asteroids are exactly that: clumps of rock weakly held together through their own weak gravitational forces.

This incidentally leads to one of the fears of trying to deflect such an asteroid were it on a collision with the earth -- that it would simply fragment it and cause destruction on a wider scale.

Re:A lot of astronomers don't want to count Pluto

[SEWilco]

Yes, it would be so much better to just reshape the incoming rock into a long needle so we have destruction confined to only two tiny little spots, including the spot on the opposite side of the Earth.

Get to the asteroid sooner.

[DunbarTheInept]

The key to preventing an extinction-causing asteroid impact is simply to NOTICE it early enough and have a fast means to get a vehicle there. The reason the asteroid-defeating plans are so hard to create is that we have to wait until the asteroid is near us before we can reach it. By then it's too late. If we can affect it sooner, then exploding it into parts could work really well because the parts would be imparted with enough velocity to spread apart so most of them miss the Earth. Even if an object is headed to strike the earth dead-center, then you only need to deflect it far enough to move it a little more than one earth-radius of distance to the side by the time it gets here and that will make it miss.
(You do need to go a little more than one earth radius because gravity will pull it in - you need to get it far enough out so it will at least slingshot around earth instead of striking it.)

To put this in perspective, if the asteroid was blown up 40 days before impact, that would give us 960 hours for it to move. In 960 hours, an object can move an entire earth radius by going a mere 4.1 miles per hour. So as long as the explosion can impart a velocity of a little over 4.1 miles per hour perpendicular to the course of the asteroid, then the asteroid bits will veer far enough off course to miss. So exploding the asteroid and sending it's parts off in different directions *can* work, if your explosion is big enough to impart that much velocity, and (this is the hard part) you can get a vehicle carrying the bomb out there 40 days before the impacyt.)

The best defense against such an asteroid is a better space program, with faster vehicles that don't require months of prep time to launch. That gives us the time for a simple solution to actually work.

Re:A lot of astronomers don't want to count Pluto

[1u3hr]

I'd prefer that. In an extreme situation, where the object would be fragmented to a bunch of dust & powder, everything would get burned up in the atmosphere. I could be wrong, but that's where I'm placing my bets.

From Phil Plait's Bad Astronomy: Review of Deep Impact [badastronomy.com]:

This was the Biggest Baddest Astronomy in the movie. Blowing up a comet does no good at all, and might even make matters worse. Just because the pieces are smaller doesn't mean you have changed anything. If every piece still impacts the Earth (by that I mean actually is stopped by the Earth or its atmosphere) you are still dumping all the kinetic energy of The Comet into the Earth's atmosphere! That's a HUGE amount of energy, dumped in practically all at once. It would still create a massive explosion, dwarfing all of our nuclear bombs combined. Even if you could somehow soften the blow, all that heat would wreak havoc with our weather. Some people actually think it might be better to simply let a big one hit rather than blow it up, because the Earth itself can absorb the energy of impact better than the atmosphere can. This is still argued, though. I'd prefer not to try any experiments!

Re:A lot of astronomers don't want to count Pluto

[Entropy2016]

I've got a couple possible solutions regarding the debate over labeling something a planet.

1. Why not just call all solid [and liquid?] bodies "satellites" ? Asteroid, planet, moon, deathstar, they're all satellites from now on.

OR

2. Redefine "Planet" to mean: Any satellite of a star with enough mass to retain an atmosphere of any [detectable?] pressure.

Rocks come in all sizes, so we ought to ditch the term or define it with respect to something as arbitrary as size.

Our universe is hopelessly complex. Accept it. Part of life as a human is dealing with a world that impossible to fully predict or control. If we didn't have such a world, things would be far less interesting. (we might even be wishing that there would be issues to debate).

Re:A lot of astronomers don't want to count Pluto

[pfdietz]

There are no planets with 'subzero cores'.

Re:A lot of astronomers don't want to count Pluto

[Jesus 2.0]

Pluto should be labeled an asteroid since it's smaller than even our own moon.

Frankly, I don't understand this line of reasoning. Why does it matter, with regards to whether something is a "planet" or not, whether that thing is bigger than, for example, our moon?

And "asteroid"? Pluto is far, far larger than anything currently considered an "asteroid".

Jupiter and Saturn both have moons that are bigger than Mercury. Do you not consider Mercury to be a "planet", either?

What if Jupiter had a moon bigger than Earth? That's not unimaginable; would Earth then not be a "planet"? In fact, would then nothing be a "planet" except Jupiter, Saturn, Uranus and Neptune?

I frankly don't see what's wrong with (something like) a "planet" being a non-star that's orbiting (directly) around a star. Sure, that makes for some seriously small "planets" relative to what we're used to, but at least it's not an arbitrary and useless definition like (no offense) yours.

And anyway, if you want to add back in your preferred amount of arbitraryness, you can always start referring to "major planets", "minor planets", and so forth.

Re:A lot of astronomers don't want to count Pluto

[mysticgoat]

Quoth grandparent: Pluto should be labeled an asteroid since it's smaller than even our own moon.

Quoth parent: Frankly, I don't understand this line of reasoning. Why does it matter, with regards to whether something is a "planet" or not, whether that thing is bigger than, for example, our moon?

I agree with parent that in this case size really doesn't matter: it's all in how you use what you got.

Historically, Neptune was discovered because it was perturbing Uranus' orbit: its existence was theorized long before it was directly observed. Similarly, Pluto was discovered because it was found that Neptune alone was not sufficient to account for all of Uranus' irregularity. While Pluto isn't very big, its size and orbit are such that it definitely affects the other planets.

In practice then, what we have actually used to distinguish a planet like Pluto from a large body that is not a planet, like Chiron (roughly as big, discovered 1977), is whether the object interacts in a measurable way with known planets. If it does, then accord it planet status because it is clearly part of the planetary system.

In view of this, the new discovery is probably not a planet, unless it has a weird orbit like Pluto and would account for some of the remaining difference between planetary observations and expectations.

But what do I know? IANAA.

Re:A lot of astronomers don't want to count Pluto

[Yunzil]

Similarly, Pluto was discovered because it was found that Neptune alone was not sufficient to account for all of Uranus' irregularity.

Actually, no. When Pluto was discovered it was found to be too small to account for the irregularity in Uranus's orbit. When they went back and checked, they found there had been a mistake and there wasn't any irregularity to start with. The discovery of Pluto was an accident.

Re:A lot of astronomers don't want to count Pluto

[CrazyTalk]

I remember hearing awhile back when the debate was raging about Pluto that to be a planet, the object has to be sufficently large so that gravitational forces caused it to form in the shape of a sphere. So, varous small hunks of debris orbiting the sun definately are not "Planets". At the other end of the spectrum, objects large enough to radiate a certain amount of heat are considered stars. Neither of these definitions are exact, and the astronomy dictionary will probably need to be rewritten with all the recent scientific discoveries emerging, but there are some definitions out there that are not completely arbitrary.

Re:A lot of astronomers don't want to count Pluto

[r2vf]

IMO, Pluto should [shouldn't?] be labeled an asteroid since it's smaller than even our own moon [wikipedia.org].

An interesting point, though to be fair, its an arbitrary cutoff. There are moons elswhere in our solar system larger than Mercury, which is indisputably a planet, for example. Also its worth pointing out that our moon is large enough that it and Earth are sometimes called a double planet. Consider this, Luna does not orbit Earth as near the equator as is usual among most other moons. Also, peculiar to all 138 known moons with the exception of Charon, it possesses an orbit where the effect of the Sun's gravity is greater than that of Earth's. Without their host planets, they would float off, wheareas the moon would continue orbiting the sun quite contently.

Re:A lot of astronomers don't want to count Pluto

[el-spectre]

To be fair, luna is also the closest moon to the sun by a hundred million miles...

Escape velocity

[geoswan]

Without their host planets, they would float off, wheareas the moon would continue orbiting the sun quite contently.

I have been interested in Astronomy since I was about six years old. Just over forty years. I have heard what you suggest before -- but only in the last few years. And I don't understand it any more this time than I did on the earlier occasions.

Frankly, I strongly suspect it is a false factoid, like that the internet was built to survive a Nuclear War. I strongly suspect it is a bullshit meme that keep being repeated because it sounds cool, but is completely false.

Pray explain what you mean when you say the other 138 moons would float off ?

I am trying to do the "thought experiment" of silently, quietly erasing the principals of those moons, mass and all. I am finding this difficult to do. I don't believe there is any way this could occur, in our Universe.

So, instead I imagined doing something to accelerate a moon, any moon, to the escape velocity of its principal. What happens then? Well, the object accelerated to just beyond a planet's escape velocity will assume an orbit very similar to that of the Planet it just escaped from. Sometime in the last couple of years ago there was a flap about a small object [slashdot.org] that seemed to have been temporarily captured in the Earth-Moon system. But it turned out to be NASA space debris. It appeared to be the discarded upper stage of an Apollo moon shot.

Re:Escape velocity

[Doomdark]

false factoid, like that the internet was built to survive a Nuclear War.

Perhaps it's a typo from your part -- original Arpanet was certainly designed such that a network could be built that would survive effects of parts of network to be completed wiped out; something that could happen as a result of nuclear strike. I don't think Arpanet infrastructure itself was more than a (eventually large-scale) prototype (physically, I mean; protocols were certainly engineered correctly), and thus neither it, nor Internet later on, was built to be as tolerant as what protocols would allow.

That Arpanet was designed to survive catastrohic (yet not completely destructive -- there still has to be at least one route between nodes that want to communicate, obviously), is not an urban legend , and should be easily verified from various accounts by its creators.

Technically, the moon is a planet

[MickLinux]

The moon's orbit is everywhere concave towards the Sun. Therefore, the moon is a satellite of the Sun, and not a satellite of the earth. As such, perhaps it should be called a member of a binary planetary system.

Re:Technically, the moon is a planet

[jeisner]

The moon's orbit is everywhere concave towards the Sun. Therefore, the moon is a satellite of the Sun, and not a satellite of the earth. As such, perhaps it should be called a member of a binary planetary system.

Here are pictures and discussion [nus.edu.sg] of the moon's orbit about the sun.

Re:A lot of astronomers don't want to count Pluto

[catbutt]

So where's the line between asteroid and planet?

Why does there have to be one? Man's tendency is to compartmentalize things, to make sure everything has a name and that name is unambiguous. Problem is, nature doesn't cooperate. There are always going to be intermediate forms, so there are never going to be definitions that aren't arbitrary.

Same thing applies to species. The nice simple definition "if it can interbreed, its the same species" doesn't always work, and there is no reasonable definition that covers all cases and removes ambiguity.

A decision based on Science, or Politics?

[geoswan]

Is this a decision based on Science? Or is it based on Politics and emotion?

Did you know that in 1998 Senator Patrick Leahy, of Vermont, got his State's largest Lake, Lake Champlain, to be reclassified as the 6th Great Lake? [dencities.com] At least as far as the awarding of researh grants. Being considered a "Great Lake" made the academic institutions in his constituency eligible to apply for certain research grants.

There is talk of sending a probe to Pluto. Is it possible that it is easier to sell a probe to "planet Pluto" than to send one to Kuiper-belt object Pluto?

I remember, back in the days when I tuned in to debates as to which newsgroups should be created, the big debate as to whether a new group should be talk.acquaria, rec.acquaria or sci.acquaria.

In Leahy's defence, these were environmental research grants, and I should probably assume he added this line to the bill to protect his constituent's natural environment -- not for the petty partisan purposes.

What about atmosphere?

[Rick the Red]

What we need is a simple rule: If it orbits a star and has an atmosphere, it's a planet. If not, it's not. I.e., things orbiting other planets are moons, even if they have an atmosphere. Things orbiting a star are asteroids (or whatever) if they don't have an atmosphere, no matter how large they are.

Pluto has an atmosphere [spacetoday.net], so it's a planet. What about Sedna? Does anyone know, or must we wait until Monday?

Re:What about atmosphere?

[beeplet]

The presence/absence of an atmosphere is not as clear-cut as you might think... Both the moon and Mercury have comparably thin atmospheres. Are they both planets or both asteroids? Pluto may currently have an atmosphere, but it may freeze to the surface as the planet moves away from the sun. Will it cease to be a planet?

Picture of new planet:

[big_groo]

Here----> .

Woop de fucking do!

[Operating Thetan]

Cue conspiracy theories, New Age freaks, Planet X believers and other idiots. Still, at least this discovery has the redeeming quality of completely fucking up astrology

Re:Woop de fucking do!

[Amiga Lover]

I want to know what happened to Quoaor or whatever the hell it's name is. wasn't it planet 10 last year?

Re:Woop de fucking do!

[beebware]

It was called Rupert.

Re:Woop de fucking do!

[JayBlalock]

It was only something like 1,400 klicks across, if memory serves. So this new find does at least have the distinction of being substantially larger.

Re:Woop de fucking do!

[Snowspinner]

Yeah, it'll probably cost a lot to reprint all the New Age ancient traditions to include a tenth planet.

Re:Woop de fucking do!

[Anonymous Coward]

Yeah, it'll probably cost a lot to reprint all the New Age ancient traditions to include a tenth planet.

Ten Planets? You haven't been keeping up with here astrology has been going the last twenty-fove years. I know astrologers who use twenty planets, most of which are imaginary. [ Dutch School of Astrology. Germans School of Astrology. The Planets of Alice Bailey, and related flakes.]

This, of course, ignores the two hundred or so asteroids which new age astrologers use. And don't forget the plethora of comets, meteor showers, deep space objects, and other things that may, or may not exist.

And to be sure that you haven't forgotten anything, there are umpteen "Arabic Parts", Midpoints, Orbs, harmonics, ( or something like that) etc.

In short, roughly 10^8 objects that no self-respecting astrologer would omit, if one believes in the validity of all the books on astrology that have been published.

Re:Woop de fucking do!

[Jesus 2.0]

The way astrology works is ... not at all?

Re:Woop de fucking do!

[osgeek]

Now, of course that seems like hogwash, and maybe it is, but it is pretty accurate

Bullshit. If it's accurate, then you could come up with a test to prove it. You could take astrological predictions for an individual based upon his house and compare them with random predictions. These could then be compared for statistical validity, proving once and for all that astrology is accurate.

Wow, if only someone would take the time to perform tests like these. Maybe someone could even make a contest to offer money to anyone who could prove a fantastic claim like "astrology is accurate". [randi.org]

Get it through your skull. It's PROVEN TO BE bullshit. It's always been bullshit, and it will always be bullshit. I've had close dealings with astrologists. I know how some of what they say can seem to be more than just coincidence, but that's all it is -- coincidence and psychology. It's got nothing to do with anyone's "house" or "fate". It's all just bullshit. Don't be a sucker.

Re:Woop de fucking do!

[Anonymous Coward]

Yeah but just think of all the new Christian derivatives that can arise! 10 COMMANDMENTS! 10 PLANETS! COINCIDENCE? I think not.

Please send donations now to my paypal account to start our new church.

Re:Woop de fucking do!

[S.O.B.]

But then the evolutionists would respond with, "10 planets, ten fingers. Coincidence?"

Re:Woop de fucking do!

[cybermace5]

Wanna know what will REALLY give the conspiracy theorists, New Age freaks, etc? "Sedna" is "Andes" spelled backwards! Everyone knows the advanced Inca civilization lived in the Andes mountains, and there are more than enough wacky theories about the Incas involving aliens and whatnot. Oooh...why is an Inuit god named after backwards-Andes...are the Inuits actually Inca refugees? They're close the Pole, too, and there are already crazy theories about a hole to the interior of the earth where advanced civilizations live, and the Eskimos are somehow related....

Yeah, can't imagine a worse name, really. Backwards-spelled stuff is pure gold in the conspiracy community.

Yeah, but

[niom]

what isn't pure gold to the conspiracy community?

Astrology = Syncretic Religion

[handy_vandal]

Still, at least this discovery has the redeeming quality of completely fucking up astrology.

Astrology doesn't work that way.

Astrology is syncretic religion [google.com] -- it readily (and inevitably) incorporates new influences.

Like an amoeba, astrology engulfs everything it touches.

In this sense, astrology is rather like paranoia: everything pertains, everything is part of the Big Picture.

Sedna won't fuck up astrology. On the contrary, astrologers will eagerly seize on the idea of this new planet, treating Sedna as one more vacuole in the amoeba.

-kgj

I wonder what is so important....

[dealsites]

I wonder what is so important that NASA is going to wait until Monday. Maybe they will be unveiling something else at the same time?

--
Real-time deal updates [dealsites.net]

Re:I wonder what is so important....

[AnamanFan]

It's a standard rule of Public Relations. Never announce anything between Friday at 4pm till Monday at 8am.

The reason being that news outlets are not at full capacity during the weekends, so any news announced over the weekend won't get as much coverage. If NASA announced the news today, it will be covered on the Sunday evening news, and never again since that piece of news was already done, even when not many saw it.

You can notice this practice when someone famous dies over a weekend. There will be an immediate announcement saying that the person is missing or very ill or something of the sort, then make the announcement on Monday.

Re:I wonder what is so important....

[Bearpaw]

It's a standard rule of Public Relations. Never announce anything between Friday at 4pm till Monday at 8am.

Unless, of course, it's something you have to announce for some reason but don't want most people to hear. Then late Friday afternoon is the perfect time to announce it. Politicians do this a lot. It would probably be quite instructive to review Friday late-afternoon press releases from the White House, for the last two or three decades.

Re:I wonder what is so important....

[gnu-generation-one]

"I wonder what is so important that NASA is going to wait until Monday. Maybe they will be unveiling something else at the same time?"

It's the monthly bug-report announcement. "A local root vulnerability has been found in the astrology community. NASA rates it as non-critical"

whew!

[odano]

Thank god I am out of elementary school. Memorizing 9 planets was hard enough, but 10! They have got to be kidding.

Re:whew!

[LostCluster]

And what about all those M-V-E-M-J-S-U-N-P mnemonics we learned. Those already had to be retrofitted to become M-V-E-M-J-S-U-P-N, now they need to extend to M-V-E-M-J-S-U-P-N-S.

Re:whew!

[Anonymous Coward]

My very educated mother just sent us nine pizzas, sucka - Mr. T

Re:whew!

[calibanDNS]

My Very Educated Mother Just Sent Us Nine Pizza Slices.

Back to grade school for retraining...

[LostCluster]

The order of planets we all learned in 4th grade was out of date already because now Neptune is further away than Pluto. Now, I guess we're going to have to memorize another planent for the next quiz.

Re:Back to grade school for retraining...

[Professor_Quail]

Actually, they switched back in 1999; Pluto is again further away than Neptune.

Re:Back to grade school for retraining...

[thomasdelbert]

Correction - Neptune was farther from Pluto from January 21, 1979 to Feb. 11, 1999 [nasa.gov] but at this time Pluto is farther from the sun than Neptune.

Of course, there's debate as to whether Pluto-Charon is a planet with a moon, or a double planet...

- Thomas;

Re:Back to grade school for retraining...

[mark-t]

There is a simple way to decide if something is a moon or double planet. Look where the two focal points for the elipses that describe their orbits are.

If both focal points for the orbit are contained within the volume of one body, or if one focal point is contained within the volume of one body and the other focal point outside of both bodies, then the smaller object is a moon of the larger.

If both focal points are outside the volume of both bodies, or if one focal point is within the volume of one body and the other focal point within the other body, then the pair of objects should be considered a double planet.

So Pluto/Charon, following this reasoning, should be considered a double planet.

Alf

[TheGreatAvatar]

was right after all!

for comparison purposes:

[Anonymous Coward]

Pluto is 2300 km diameter, ranges from 4.3 to 7.4 billion km from the sun.

http://www.windows.ucar.edu/tour/link=/pluto/stati stics.html [ucar.edu]

It's a Kuiper object...

[meringuoid]

... and the last I heard was that it was about the size of Charon. I doubt it will ever be recognised as a planet - we already have Quaoar out there and swarms of other little Plutinos.

Whether Pluto is 'really' a planet or just a big Kuiper object seems to be a silly argument. Even if it's not justifiable, we'll call Pluto a planet out of tradition.

Re:It's a Kuiper object...

[Gutboy_Barrelhouse]

No. Charon is slightly smaller than Quaoar.

Sedna is over 4 times the size (volume) of Quaoar.

Whether it's a planet is a silly argument, but even so, "we already have Quaoar" is really irrelevant.

Planet is not a useful category.

[AlecC]

The concept of Planets should no longer be regarded as a formal (as opposed to colloquial) classification. We have four rocky inners, four gassy outers, and a vast number of planetismals. Forming a group of the first two classes, with or without a few of the last, is a false classification.

Re:It's a Kuiper object...

[RobertFisher]

The question becomes even more convolved once we move outside the solar system, since we now know of a wide diversity of systems, of which our own solar system is only one particular instance. (And perhaps not even typical at that.) We know that there are objects extending all the way down from massive stars (around 100 Msun) to hydrogen-burning stars like our sun to brown dwarfs to planets. Clearly any definition of a planet must apply not only to our solar system, but also to these extrasolar systems. Some of these systems are much like our own (for instance, they may contain a brown dwarf orbiting a star, or a planet orbiting a star), and some (including a few systems of low enough mass to qualify as a planet) are "free-floaters" -- just sitting out there by themselves in space.

I think ultimately the question is whether there is a single continuous "initial mass function" of isolated objects or not. The best idea as to how stars acquire their initial mass is that turbulence in the interstellar medium, which exists on all scales, establishes a power-law distribution of initial masses. Every once in a while, you get a very strong shock which passes by inside a giant molecular cloud and forces the collapse of a large region which then goes on to form a massive star. But more typically, you form stars more like our sun. And just as rare as massive collapses are very small mass ones which go on to form isolated brown dwarfs and free-floating planets. If this model holds up to be true, then we are all mincing words in our definitions of isolated systems, since they are all manifestations of the same universal formation process.

However, to avoid the difficult question of formation mechanisms, an IAU working group of some of the most respected people in the field established a working definition [ciw.edu] to define by fiat what it means to be a brown dwarf, and a planet. Extrasolar "planets" are those objects orbiting a star which are beneath the deteurium-burning limit -- regardless of how they are formed. "Brown dwarfs" are defined to be those which burn deuterium but not lithium, and "sub-brown dwarfs" (NOT free-floating planets!) are defined to be those isolated objects which do not burn deuterium. Even the working group itself admitted that this definition was not satisfying to a single member of the group, and so it is likely it will be replaced at a later time with something more physically-motivated. The "planet/planetismal/KBO" distinction was pushed back to our own solar system, since it will be some time before anyone sees anything that small in another system.

Also of interest is the following link, which gives a history of previous claims for additional planetary members of our solar system : SEDS [arizona.edu].

What happened to the naming convetion?

[Snowspinner]

I thought planets were Roman gods. It's not even like we've run out of them. We can still find Vulcan (Mulciber if you want to avoid rabit Trekkies), Juno, Minerva, Apollo (You can call this one Phoebus if you want to avoid confusing it with space probes), Diana, Vesta.

And that's before you start getting slightly obscure ones like Janus, Bacchus (Or Liber), Fanus, Quirinus, Pomona, or Vertumnus.

Re:What happened to the naming convetion?

[Limburgher]

Janus is already a moon of Saturn, IIRC.

Re:What happened to the naming convetion?

[hobbesmaster]

IANAAP, but Vulcan is already reserved, it was a theoretical planet in the early 20th century that would be closer into the Sun that Mercury's orbit that would account for irregularities in Mercury's orbital path. There was actually no planet and Mercury's behavior is proof of the special theory of relativity (IIRC).

I'd presume that for historical reasons Vulcan would be reserved. Also recall that theres lots of trans pluto pluto sized objects that have names, I forget what the naming mechanism is for them, but I think they're roman.

Re:What happened to the naming convetion?

[volsung]

The precession of Mercury's orbit is explained by the general theory of relativity, not the special theory. The special theory explains the results of the Michelson-Morley experiment.

Re:What happened to the naming convetion?

[Sqwubbsy]

Wasn't 'Apollo' considered the sun. Remember, this wasn't just a 'naming convention' but actual mythology. Apollo drove the chariot of the sun across the sky. Mars, the god of war, appeared in certain places at certain times, same with Venus.
Now that Roman mythology isn't really considered religion (outside of Berkeley) it can be a nice tradition. I mean, it's not lik the Inuit have really contributed to Western Culture except for, I guess, hockey and lacrosse.

Inuit Contributions

[Vagary]

Hockey was invented somewhere in Europe or European North America in the 19th century. Lacrosse was invented by Indians near the St. Lawrence and is played on grass rather than snow, so I doubt the Inuit were involved.

Inuit inventions include snowshoes, toboggans, dogsleds, kayaks, toggle harpoons, and various other tools for hunting and travelling in the North as well as snow and ice civil engineering techniques. Pretty impressive, I'd say, for a culture with almost no wood, rock, or metal. They've probably contributed as much as any other non-Eurasian colonialised culture, and they make some really cool art.

Re:What happened to the naming convetion?

[I don't want to spen]

Vesta [solarviews.com] has already been used.

I claim it

[AbstracTus]

Please email resident applications to me.

Re:I claim it

[s20451]

You can only call interplanetary dibs if you can see the planet as you call it. Just like calling shotgun.

They

[chadseld]

They should call it rupert.

There could be a lot of stuff out there

[mbone]

Out in the Kuiper belt and the Oort cloud [arizona.edu] there are thought to be as many as one trillion objects - most small 1 to 10 km chucks of ice.

The really interesting question is, what is the mass distribution ? (I.e., how does the number of objects scale with their mass ?) This is basically unconstrained by real data. All such cosmic mass distributions are steep, but many (for example, planets in the Solar System, Asteroids in the Asteroid belt) are dominated by the most massive bodies.

If this holds true in the Oort cloud, in particular, there could be some pretty big objects. Even a Jupiter sized object might be able to hide from the Infrared surveys (the best way of detecting such an object).

Re:There could be a lot of stuff out there

[mikerich]

If this holds true in the Oort cloud, in particular, there could be some pretty big objects. Even a Jupiter sized object might be able to hide from the Infrared surveys (the best way of detecting such an object).

Clyde Tombaugh who discovered Pluto performed an exhaustive search for Planet X for several decades. From his results he concluded that there were no undiscovered Jupiter-sized bodies within 470AU of the Sun, and no Neptune-sized objects with 210AU. (Pluto is never more than 50AU from the Sun).

The Oort Cloud is believed to have been populated by planetismals thrown out of the early inner part of the Solar System by the formation of Uranus and Neptune. They would have slungshot smaller bodies into the outer darkness into orbits that match the hypothetical orbits in the Oort Cloud. They would not have been able to shunt anything larger out that far - at least not without disrupting their own formation.

A further problem is that planet formation models run into trouble this far out. Distances between the planetismals that made up the proto-planets would have been so great, and relative velocities so small that its hard to see how they would ever have collided to built up a bigger planet.

Best wishes,
Mike.

Yuggoth found--details and photos at 11.

[sudog]

I for one welcome our new Mi-Go masters!

Political Correctness

[schnarff]

I think I can answer all of the people on here who are asking "Why didn't they go with a Roman name?". It's real simple: political correctness. After all, Roman names were given to the planets by a bunch of old, dead white men, and are a vestige of a conquering, warfaring civilization. This new Inuit name represents one of those poor, marginalized, powerless indigenous tribe types. It's like affirmative action for planets.

Personally I think we should have just stuck with the Roman names and kept a consistent system...but then again, I am a middle-class white male. ;-P

10th planet is more fun so it is in

[SmallFurryCreature]

Screws up astrology and that can only be a good thing. Lets add one every 2-3 years and watch them squirm.

Anyway something 2000km in diameter is hardly small. Aren't astoroids that could kill earth just a couple of kilometers accross?

Anyway excluding it is sizeist. Can't have that. If you are going to classify keep it simple. Object larger then a rock orbetting the sun and being close to round. I think that is what most people consider a planet.

So welcome sedna.

Re:10th planet is more fun so it is in

[TomHandy]

Hrmm, I agree screwing up astrology is always a good thing. But what if this HELPS them? What if now astrologers defend all their false "predictions" by explaining that it was in fact Sedna's influence that skewed the results?

-Tom

Not a problem yet

[SiliconEntity]

It won't be an issue until they find a Kuiper object that is bigger than Pluto. Then they'll have an awkward situation. Making Pluto a planet when this bigger object isn't one doesn't make sense; nobody wants to add a new planet, because in retrospect it was a mistake to make Pluto a planet, and adding another Kuiper object would just compound it; and removing Pluto from the list of planets offends tradition.

Everyone wants to push this off as long as possible, so if the new object is really smaller than Pluto, they'll breathe a sigh of relief and go on with things as they are.

That would be 11th!

[Vo0k]

Quaoar [independent.co.uk] (though some claim it's too small for a planet...)

Alf predicted them both!

If I remember

[bigattichouse]

There was a formula for predicting orbital paths that was related to Fibbunaci's sequence, I wonder if sedna falls into the sequence?

Bode's Law

[Gorimek]

That would be Bode's Law [wikipedia.org]. It is wiewed as more of a coincidence than a law these days.

According to my hung over calculations Sedna is 67 AUs out, which is not that far off from the 77.6 that Bode predicts, but not really close either.

Non-Roman? Okay, community protest time!

[pla]

Sedna? No. Plenty of people in this thread have complained about two facts - One, our planets have names derived from the Roman, not Inuit, panthon. And two, we already have a planet named after a sea-god, ie, Neptune.

So, I propose that in protest to such a blatant attempt at PC Multiculturalism, we as a community refer to the tenth planet as Nox, the Roman goddess of night. Since it lies the furthest from the sun, that actually fits it, in a descriptive sense.

Sedna... Whatever. Remember, we hear about this stuff months before your typical Fox news junkie, and people tend to respect us as sources of information. So spread the word - We have a new, tenth planet, named Nox. Sedna? Nope, they must have heard wrong. Nox. Nox? Nox!

I think Lectra would be a far better name...

[bpd1069]

for obvious reasons...

on being a planet or something less...

[joebeone]

My former advisor here at UC Berkeley, Gibor Basri, has a neat way of discriminating between planets and the lesser (comets, asteroids, etc.). His idea is that if the object has enough self-gravity to force it into a spherical shape, it's a planet... if it doesn't (like Mars' "moons"), it's something less.

Here's a snipet:

How can this be resolved? A consensus is slowly developing (I believe) for the following solution. We can first define what we mean by "planetary mass", and base this only on physical characteristics. Then we can include circumstance into the definition of "planet". I propose the following three definitions:

FUSOR - an object that achieves core fusion during its lifetime.

PLANEMO - a round non-fusor.

PLANET - a planemo orbiting a fusor.

[...]

read on for his full article [berkeley.edu].

The following is a draft of an article now published in the Nov/Dec 2003 issue of Mercury. Draft of Mar. 20, 2003.

Defining "Planet" by Gibor Basri Univ. of California, Berkeley

Even before they were civilized, people looked into the sky and recognized different celestial objects. The Sun defined daytime, and the stars provided a fixed background of faint, twinkling lights at night. Among them moved the Moon, and a few special steadier lights. The Greeks called those which moved "planets" (it is worth noting that the Sun and Moon were originally included, since motion against the stars was the defining characteristic). Most cultures have an analogous word for these "wanderers". Both the stars and the planets were thought to revolve around the Earth.

After the Copernican Revolution, we recognize the Moon as the only body that orbits the Earth. The Sun is a very nearby example of a star, and the visible planets are other large bodies that orbit the Sun. We see them by reflected sunlight, while stars produce their own visible light. This understanding yields the dictionary (lay public) definition of the word "planet": a large heavenly body that shines by reflected light and orbits the Sun. In the past century we gained much understanding of our Solar System, and even visited most of the planets robotically. Yet today, professional astronomers find themselves unable to agree upon a succinct definition of "planet". Replacing "the Sun" with "a star" is obviously necessary now that many extrasolar planets have been discovered, but the problem goes well beyond that.

Two recent controversies that found their way to the popular press illustrate further difficulties. One is the "Pluto controversy". This arose because of the discovery of a large belt of icy objects beyond Neptune. They are the outer remains of the original protoplanetary disk. This "Kuiper Belt" is a natural outcome of incomplete planet formation in the outer Solar System, and is the source of some of the comets we see. As Kuiper Belt objects (KBOs) were discovered in increasing numbers in the 1990s, including a population of "Plutinos" which share Pluto's orbital characteristics (somewhat different from the other planets), some astronomers began to suggest that Pluto itself (which shares many properties with, but is the largest KBO known so far) does not qualify as a planet. The recent discoveries of Varuna and Quaoar (which are KBOs half the size of Pluto, like its moon Charon) may presage the time when we find another Pluto-sized KBO.

The current situation is much like that in the early 1800s, when the first asteroids were discovered. Ceres was originally hailed as the fifth planet, particularly since one in its position was expected from "Bode's Law" of planetary spacings. It lost its status within a few years, when other members of the asteroid belt began turning up. Herschel, who had been the only person to have discovered a new planet before then, aided the effort to demote Ceres. The arguments against its planeta

This will be handy for sysadmins...

[Boss, Pointy Haired]

This will be handy for those short-sighted sysadmin types that name their servers after finite sets like planets.

Now they'll be able to buy up to 10 servers before re-thinking their naming strategy.

Re:How could

[dreamchaser]

Because you have to be looking at the right place at the right time. Do you have any idea how vast a volume of space we're talking about?

Re:How could

[Limburgher]

Not to mention that in the Hubble's field of vision, a local planet would be moving much faster than a star millions of AUs out. Imagine looking through binoculars at your sexy neighbor sunbathing in her (or his) yard. You might not see the gnat flying a foot in front of you, because you're not focusing there, so it would just be a blurry fuzz, possibly ignored by the eye if visible at all.

The binoculars also limit or eliminate local vision while in use, obscuring the approach of your spouse/mother and a disapproving hand. . .:)

Re:How could

[phch]

It's always been hard to see distant planets because they don't emit light. Hubble can see distant galaxies because they contain lots of luminous objects.

Re:How could

[imsabbel]

"FAR" is a very vague thing in space.
Yes, its near, but its small and its cold. So its only to detect if you are looking EXACTLY at it.
A blue giant a million light years away is MUCH easier to spot that that pile of cold rock.

Re:How could

[Sqwubbsy]

"FAR" is a very vague thing in space.

I hear they're going to adopt the new distance measures 'hither' and 'yonder' so normal folks will have a better understanding, at least in galactic terms, of where things are.

Re:What, no more Roman gods?

[JeffTL]

I believe it's called "patronizing faux multiculturalism" -- if a Roman name for it becomes available, count on me to use it as much as possible.

Re:What, no more Roman gods?

[JayBlalock]

Actually, yes. Thanks to them assigning minor moons the names of deities, they've pretty much run out of Roman gods, Greek alternates, and have even put a pretty good dent in the Norse pantheon.

Re:What, no more Roman gods?

[meringuoid]

The hypothetical tenth planet already has a name, assigned to it by common consensus of SF authors. It's Persephone, the bride of Pluto.

That said, my classical mythology is rusty: I think Persephone was the Roman one, daughter of Ceres, and Proserpina was the Greek one, daughter of Demeter - but I might be wrong. Time to inquire of the Overmind we call Google, methinks...

Re:What, no more Roman gods?

[Concerned Onlooker]

I don't care about the Roman gods much, but I am puzzled as to why they would pick a goddess of the sea when it doesn't seem likely that the new planet holds much water. Perhaps we should name the new planet Earth and rename our own rock Sedna?

Re:What, no more Roman gods?

[pajamacore]

They might have chosen the name Sedna because the object is in the Kuiper Belt. If I recall correctly, the naming convention for Kuiper Belt Objects is that of creation deities. Sedna is the most important deity to the Inuit and plays a vital role in one creation tale, what with her parents chopping off her fingers and those fingers turning into various aquatic animals.

Re:What, no more Roman gods?

[M1FCJ]

I feel insulted. I'm an atheist and I don't like these stupid god names polluting skies. What's the matter with these people? Can't humanity grow out of its infantile and get rid of this gods&belief nonsense?

The Inuit myth of Sedna

[Futaba-chan]

If I recall correctly, the naming convention for Kuiper Belt Objects is that of creation deities.

Sedna isn't actually a creator goddess -- she was born mortal, and became a goddess when the spirits of the air and the moon decided to reward her for her suffering in her mortal life, as she was drowning. Two accounts of the Sedna myth may be found here [hvgb.net] and here [inuitgallery.com].

In any event, aren't you glad that they're naming it Sedna, and not Uinigumasuittuq?

Re:Closer to home

[ScrewMaster]

Yes, and they're getting less and less heavenly all the time.

Umm...Mars?

[0x0d0a]

don't know if anyone else feels this way, but I'm kind of let down by the fact that our most interesting space story for awhile now is that we MAY have a 10th planet in our solar system.

Umm...what? The past few months have been *spectacularly* exciting from a space point of view. We have two probes that successfully landed on Mars and have found strong evidence that Mars had liquid brine at one point. We have a ton of pictures from the surface to look at, and are expecting tons of findings, papers, and theories based on probe data that's been returned.

And while, yes, the classification may not be interesting, the fact that we discovered a new, sizeable chunk of matter in our solar system is not small stuff either.

Re:I wish NASA was better at PR..

[0x0d0a]

Dude, *how* can you possibly blame NASA for insufficient coverage?

They put out an entire *channel* of content and have an extensive website with tons of goodies. They have been fighting like mad to get more media coverage to ensure that they get continued funding.

If you want to blame someone, blame our current media sources or people's interests. NASA is the *least* guilty party involved in trying to expose people to information about space.

Re:I wish NASA was better at PR..

[Awptimus Prime]

If you want to blame someone, blame our current media sources or people's interests. NASA is the *least* guilty party involved in trying to expose people to information about space.

So NASA could put the next release on NASA TV instead of just having a conference call with reporters. Like you say, the station is there 24/7. It's fully funded to run programming 24 hours a day, so to broadcast their findings won't cost anything.

Have you watched the NASA channel? When there's not a news release, it's 0 budge